The invention belongs to the field of measuring instruments, in particular to a large mechanical force measuring machine. The novel mechanical force measuring machine mainly consists of a machine body, a frame, a weighing sensor set, a power mechanism, a pressurizing mechanism, a compression displacement multiplication mechanism and an operating instrument, wherein the power mechanism is composed of a stepper motor and a cycloidal-pin wheel decelerator and fixed above a base of the machine body; the pressurizing mechanism is composed of a pressurizing screw rod and a screw nut, and a forced direction of the pressurizing mechanism is changed by a force transmission lever; for bringing convenience to calibration work of the force measuring machine, an integrated package-type frame is composed of a frame with four upright posts and the compression displacement multiplication mechanism on a surface of a bearing table; and the displacement of the frame is increased by ten times in comparison with the deformation of a sensor per se by compressing a disc spring in the compression displacement multiplication mechanism to shrink under pressure. In an embodiment of the invention, a measurement precision value can easily reach 1/640,000.